Alaska’s wild frontiers are the opposite of the luscious jungles and tropical swamps where most people think dinosaurs lived. Yet paleontologists are discovering a remarkable diversity of unique species lived above the arctic circle 70 million years ago – where they had to endure freezing temperatures, food shortages and at least four months of total darkness.

Now, Dr Pat Druckenmiller and Dr Greg Erickson embark on two gruelling expeditions, to the vast arctic tundra and unchartered alpine wilderness, in search of buried fossils and elusive trackways which overturn our understanding of the prehistoric world. Who lived here and how could they survive?

Working with world-class researchers they explore the geology and climate of an extinct polar environment and the adaptations – diet, hibernation, thermoregulation – which helped dinosaurs not only to survive but to thrive in it, even finding tantalising evidence of multiple species reproducing in the coldest parts of the planet. Using cutting-edge advances in paleontology, they can piece together the extraordinary lost world of arctic dinosaurs.